Fuse block



Aug. 2,0, 1935. J. sANDlN 21,011,654

WITNESSES: INVENTVOR Jerome Sand/'n GWW.

, ATTORNEY A ug. 20, 1935. J. sANDlN 2,011,654

FUSE BLOCK Filed June 1e, 1927 2 sheets-sheet 2 INVENTQR Jefa/fleSand/'rv ATTRNEY Patented Aug. 20, 1935 PATENT OFFICE FUSE BLOCK JeromeSandin,

Penn Township,

Allegheny County, Pa., assignor to Westinghouse Electric & ManufacturingCompany, a corporation of Pennsylvania Application June 18, 1927, SerialNo. 199,708

16 Claims.

My invention relates to fuses and more especially to fuses forhigh-voltage services.

One object of my invention is to provide a fuse block that shall haveincreased creepage distance between the live parts and' ground.

Another object of my invention is to provide a fuse block constructed ofinsulating material that shall have the characteristic of absorbing nomoisture.

A further object of my invention is to provide a fuse block that shallhave a cover constructed of molded glass for permitting the inspectionof the interior without the removal of the said cover.

A still further object of my invention is to provide a method ofdrainage that shall prevent collected moisture or rain from wettingcertain portions of the surface of the fuse block, thereby maintainingits effectiveness against electrical breakdown in all Weatherconditions.

Heretofore, fuse blocks of molded material have been limited in theirvoltage capacity because they were constructed of materials thatabsorbed moisture and because of the limited striking distance betweentheir electrical conducting elements and parts connected to ground. Inpracticing my invention, I am able to increase the creepage distancebetween the live parts and ground by surrounding the insulating base onwhich the live parts are mounted with a deep groove, the outer rim ofwhich forms an insulating skirt that-protects the surfaces which itencloses from weather and dust, thereby materially increasing thecreepage surface from the live parts to the support on which the fuse ismounted.

By the use of insulating materials which do not absorb moisture, such asglass or glazed porcelain, I am able to employ my fuse blocks onelectric circuits of much higher voltage than has heretofore beenpracticable. If glass is used, it is desirable that it be aboro-silicate glass because of the ability of the latter to withstandthe temperature strains met with in service. Such glass is well knownand comprises substantially 80% S102, 14% B203, 4% Na2O and 1% AlzOa.The use of this glass has the further advantage that metal inserts madefrom steel, a rustless alloy comprising approximately 60% Ni, 33% Cu,6.5% Fe and perhaps small amounts of Mn, Si and C, and the like may bemolded in it, thereby eliminating the necessity `of cementing orbabbitting the insert in place, as is necessary in the case ofporcelain. Where the cover member of the fuse block is of glass, thecondition of the fuse may be determined by viewing it from the exteriorof the casing without the removal of the cover, a procedure which isundesirable in the case of fuses of this type since it necessitates theopening of the electric circuit.

In referring to the drawings;

Figure l is a side view of a preferred form of my invention and showsthe containing member and cover member in section.

Fig. 2 is a front view, in elevation, of the fuse block shown in Fig. 1.

Fig. 3 is a view of a fuse embodying my invention and shows, in section,a form of base adapted for use in higher voltages.

Fig. 4 is a side view, partly in section and partly in elevation,showing another embodiment of my invention in a fuse for higher voltageservice.

Fig. 5 is a side view, partly in section and partly in elevation,showing still another form my invention may assume.

According to the drawings, the fuse block I comprises a base member 2and cover 3, both made of molded or cast insulating material. A fuse 4,which may be of the expulsion type, is attached to the cover 3, the twoforming a unitary structure supported on a pair of arms 6 which engage apair of hooks I supported on the base 2. As will be evident from Fig. 1,the cover 3 may be entirely disengaged from the hooks 1 when so desired.The fuse terminal-clips 8 engage the fuse terminal 9 when the cover 3 isin its closed position. The line wires are connected to the electricalclips 8 through terminals I0, as shown clearly in Fig. 2.

It is desirable that the line wires may enter the container 2 oppositethe upper or lower terminals III at either side. 'I'his necessitates theemployment of four perforations II in the side Walls 0f the containingmember 2, and, to prevent the ingress of moisture or rain, theseperforations are constructed with a downward slope, as shown in Figs. 2and 3.

A mounting hub I2 that is part of the base 2 is supported on a mountingbracket I3 by screws I4. In Fig. 1, the inserts for the screws I4 andother metal parts are shown babbitted in place as the structure thereinis a design using porcelain that requires this method of retaining theinserts in position. When the base is of glass, the material is moldedabout the insert, and the more expensive and less desirable method ofbabbitting is avoided.

A channel I5 surrounds the mounting hub I2, the outer rim of which is askirt I 6 which protects the inner surface of the said channel I5 frommoisture, rain, or dust, at the same time increasing the creepagesurface between the conducting parts and the mounting bracket I3. Tofurther protect the surface of the channel I5 from collected moistureand rain, by preventing it from draining therein, a raised portion I1 isprovided about a greater part of the circumference of the edge of theskirt I6, thereby forming the trough I8. This directs the water orcollected moisture that runs off the sides or top of the base 2 downalong the side of the edge of the skirt I6 and keeps the channel I5 dry,thereby retaining its effective resistance to ilashover.

If still higher voltage protection is desired, an additional ora'plurality of additional insulating skirt members I9 may be provided asshown in Fig. 3. The shirt members I9 have a raised portion II forming atrough I8 similar to that on the skirt it of the containing member t asdescribed above. I can thus obtain protection for my fuse bloclr iagainst ashover for any voltage, however large, by the addition of extrashirt members |19.

The skirt member I!) is of a Width greater than that of the skirt i6 andadds further protection to the open portion of the channel it againstmoisture and dirt.

Further protection against moisture is obtained in my design of fuse byproviding the upper front portion of the base R with a hood t!! thatprojects beyond the cover 3 and that runs part way down along its sides.The hood 2i is provided also mth raised portions il? and 23 to preventcollected moisture and rain from. running across the under surface ofthe hood 2i into the inner recess of the container Other methods forobtaining greater creepage distance over the surface of the fuse blockIl beu tween the live parts and ground are shown in Figs. 4 and 5. InFig. 4, a series of ribs 24 are formed on the mounting hub i2 increasingthe creepage distance along the surface thereof to ground. In 5, asrlrted projection 25 is @own on the top of the container it and this isthe means for supporting the entire unit. This exempiiiies the differentmethods of support that may be employed in constructing my fuse bloei;to meet the dierent field conditions, at the same time retaining thehigh flashover qualities of the modifications previously described.

It will thus be observed that I have provided a fuse block that may beemployed in a circuit of exceptionally high voltage due to its designand to the use of non-porous moisture-proof materials in itsconstruction. The design assures the greatest protection againstmoisture and provides a maximum iiashover protection to ground. VThematerials employed are non-porous, providing a moisture proof insulatingmember for the support of the live parts, and, byconstructing the covermember of a transparent substance, the interior containing the fuse maybe observed without the necessity of opening the cover and, thereby, thecircuit, as has been the practice heretofore.

It will be recognized that, while I have described a fuse block in whichboth the base and the cover are of glass, I contemplate also a structurein which only one of these members shall be of that material.

While I have shown and described a particular form of my invention,changes may be effected vtherein without departing `from the spirit andin a, mounting hub providing a support therefor, an annular channelabout the mounting hub, the outer Wall formed thereby constituting aninsulating skirt extending over the mounting hub thereby increasing thecreepage distance along the surface of the fuse block between live partsand ground.

2. A fuse box of glass having a door opening in one side thereof and achannel about a mounting hub therefor, the outer Wall of said channelconstituting an insulating skirt protecting the surface of the mountinghub and increasing the creepage distance along the surface of the fuseblock from live parts to ground.

3. A fuse box of insulating material having a door opening in one sidethereof and a vitried surface, mounting means on the side thereofopposite said door and a channel about said mounting means for said box,the outer wall of said channel constituting insulating means forprotecting the mounting means and a second insulat ing member in fixedrelation to the mounting means for increasing the creepage distance toground.

4. A fuse block of non-absorptive material .having a mounting memberintegral therewith for supporting the block, a cover for said block ofglass, an annular channel about the mounting member the outer Wall ofsaid channel constituting an insulating 'skirt for increasing thesurface of the mounting member.

5. A. fuse box including terminals adapted to support a fuse, said fusebox being of boro-silicate glass molded about said terminals and havingtop, side and rear Walls enclosing said terminals.

o. .li fuse block having an annular channel in one face thereof thecentral portion forming a mounting member for supporting the block, theouter walls of said channel constituting an in sulating skirt extendingover the central portion, and means on the insulating skirt forming a'trough lfor draining collected moisture therefrom.

7. The combination 'with a fuse bloclr, of mounting means therefore, askirt about the mounting means for increasing the creepage surfacethereof, and a raised portion about the edge of the skirt forming atrough.

il.' A. fuse block of insulating material having terminal membersadapted to be connected to a circuit, terminals for a fuse associatedwith the said circuit terminals, a mounting memberfor the blockprotruding from a portion thereof and a skirt of the same materialforming by extending the sides of the block over the mounting member.

9. A fuse block having terminals adapted to support a fuse, a mountinghub formed by a channed in a face of the block for its support, a shieldfor thehub formed by the outer portion of the channel and a projectionon the outer surface of the shield forming a trough.

l0. In a box for a circuit interrupter, rear, top, and side walls ofvitreous insulating material, a door opening in the front of said boxand a hinged door therefore, electrical terminal members mounted Withinsaid box, openings in said side Walls for receiving conductors extendingto said terminal members, mounting means for said box secured to therear Wall, and a channel extending adjacent the junction of said rearwall with said top and side walls for increasing the electrical creepagedistance along the surface of the box between said conductor receivingopenings and said mounting means.

11. In a box for a circuit interruptor, rear, top

and side walls of vitreous insulating material, a door opening in thefront of said box, electrical terminal members mounted within said box,openings in said side walls for receiving conductors extending to saidterminal members, a mounting hub of insulating material projectingrearwardly from said rear wall, and one or more mounting studs insertedin the rear end of said hub adjacent the center thereof and means forincreasing the electrical creepage distance between said conductorreceiving openings and said mounting studs.

12. In a box for a circuit interrupter, rear, top, and side walls ofvitreous insulating material, a door opening in the front of said box, ahinged door for closing said opening in the front of the box, electricalterminal members mounted within said box, openings in said side wallsfor receiving conductors extending to said terminal members, mountingmeans for said box secured tothe rear wall thereof, and a projecting finextending along the box adjacent the juncture of said rear and sidewalls between and spaced from said conductor receiving openings and saidmounting means for increasing the electrical creepage distance along thesurface of the box therebetween.

13. In a. box for a circuit interrupter, rear, top, and side walls ofvitreous insulating material, a door opening in the front of said boxand a hinged door therefore, electrical terminal members mounted withinsaid box, openings in said side walls for receiving conductors extendingto said terminal members, mounting means for said box secured to therear wall, and an integral projecting ridge extending along the boxadjacent the junction of said rear wall with both said top and sidewalls for increasing the electrical creepage distance along the surfaceof the box between said conductor receiving openings and said mountingmeans.

14. In a box for a circuit interrupter, rear, top, and side walls ofvitreous insulating material, a door opening in the front of said boxand a hinged door therefore, an upper and a lower electrical terminalmember mounted within the box, upper and lower openings in each sidewall of the box through which conductors may be extended to saidterminal members, mounting means for the box secured to the rear wallthereof, a project, ing ridge extending along the major part of thelength of the walls of the box adjacent each side thereof between saidmounting means and both said upper and said lower openings forincreasing the electrical creepage distance between said mounting meansand both of said openings.

l5. The combination with an insulating fuse housing having asupport-engaging portion on its rear Walls surrounded by a groove forincreasing the creeping surface between the outer side walls of thehousing and the support, of a bead extending along the top and sidewalls of the housing adjacent the rear wall for deflecting water awayfrom the said groove.

16. The combination with an insulating fuse housing having rear, top andside walls, a door opening in the front of said housing and a hingeddoor for closing said opening, supporting means for the housing securedto the rear wall thereof, and means for increasing the creepage distancebetween the outer side walls of the housing and the supporting meansincluding a bead extending along the top and side walls of the housingadjacent the rear wall for deflecting water away from the rear wall.

JEROME SANDIN.

